Polysomnographic effects of hypnotic drugs. A review

Insomnia and circadian rhythm: a bibliometrics study and visualization analysis via CiteSpace

Objective

The present study aimed to use CiteSpace to analyze the status of insomnia and circadian rhythm, identify the hot spots and trends, and provide a basis for future study.

Method

The Web of Science database was searched for studies related to insomnia and circadian from its inception to 14 April 2023. CiteSpace was used to generate online maps of collaboration between countries and authors and revealed hot spots and frontiers in insomnia and circadian rhythm.

Results

We searched 4,696 publications related to insomnia and circadian rhythm. Bruno Etain was the most prolific author with most publications, i.e., with 24 articles. The USA and the University of California were the leading country and the top institution in this field of study, with 1,672 and 269 articles, respectively. There was active cooperation between institutions, countries, and authors. Hot topics focused on circadian rhythm sleep disorders, circadian clock, light therapy, melatonin, and bipolar disorder.

Conclusion

Based on the CiteSpace results, we recommend a more active collaboration between various countries, institutions, and authors to conduct clinical and basic research related to insomnia and circadian rhythm. Ongoing research focuses on the interaction of insomnia with circadian rhythms and the corresponding pathways of clock genes and by extension, the role of circadian rhythms in disorders such as bipolar disorder. Modulation of circadian rhythms may be a hot spot for future insomnia therapies (such as light therapy and melatonin).

Curcuminoids, a major turmeric component, have a sleep-enhancing effect by targeting the histamine H1 receptor

Turmeric (Curcuma longa) had been considered as a universal panacea in functional foods and traditional medicines. In recent, the sedative-hypnotic effect of turmeric extract (TE) was reported. However, sleep-promoting compounds in TE have been not yet demonstrated. Curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) are the major constituents of turmeric being responsible for its various biological activities. Therefore, they can be first assumed to be sedative-hypnotic compounds of TE. In the present study, we aimed to investigate the effects and underlying mechanisms of curcuminoids and each constituent on the sleep-wake cycle of mice. Molecular docking studies, histamine H1 receptor (H1R) binding assays, and H1R knockout animal studies were used to investigate the molecular mechanisms underlying the sleep-promoting effects. Curcuminoids and their constituents reduced sleep latency and increased sleep duration in the pentobarbital-induced sleep test in mice. In addition, curcuminoids significantly increased the duration of NREMS and reduced sleep latency without altering the REMS and delta activity. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin were predicted to interact with H1R in the molecular model. In the binding affinity assay, we found that curcuminoids, as well as their constituents, significantly bind to H1R with the K_i value of 1.49 μg mL^-1. Furthermore, sleep latency was reduced and NREMS frequency was increased following curcuminoid administration in wild-type mice but not in H1R knockout mice. Therefore, we conclude that curcuminoids reduce sleep latency and enhance the quantity of NREMS by acting as modulators of H1R, indicating their usefulness in treating insomnia.

Effects of methadone, buprenorphine, and naltrexone on actigraphy-based sleep-like parameters in male rhesus monkeys

Opioid use disorder (OUD) has been associated with the emergence of sleep disturbances. Although effective treatments for OUD exist, evidence suggests that these treatments also may be associated with sleep impairment. The extent to which these effects are an effect of OUD treatment or a result of chronic opioid use remains unknown. We investigated the acute effects of methadone, buprenorphine, and naltrexone on actigraphy-based sleep-like parameters in non-opioid-dependent male rhesus monkeys (Macaca mulatta, n = 5). Subjects were fitted with actigraphy monitors attached to primate collars to measure sleep-like parameters. Actigraphy recordings were conducted under baseline conditions, or following acute injections of vehicle, methadone (0.03-1.0 mg/kg, i.m.), buprenorphine (0.01-1.0 mg/kg, i.m.), or naltrexone (0.03-1.0 mg/kg, i.m.) in the morning (4 h after "lights on") or in the evening (1.5 h before "lights off"). Morning and evening treatments with methadone or buprenorphine significantly increased sleep latency and decreased sleep efficiency. The effects of buprenorphine on sleep-like measures resulted in a biphasic dose-response function, with the highest doses not disrupting actigraphy-based sleep. Buprenorphine induced a much more robust increase in sleep latency and decrease in sleep efficiency compared to methadone, particularly with evening administration, and detrimental effects of buprenorphine on sleep-like measures were observed up to 25.5 h after drug injection. Treatment with naltrexone, on the other hand, significantly improved sleep-like measures, with evening treatments improving both sleep latency and sleep efficiency. The currently available pharmacotherapies for OUD significantly alter sleep-like parameters in non-opioid-dependent monkeys, and opioid-dependent mechanisms may play a significant role in sleep-wake regulation.

Automatic Cyclic Alternating Pattern (CAP) analysis: Local and multi-trace approaches

The Cyclic Alternating Pattern (CAP) is composed of cycles of two different electroencephalographic features: an activation A-phase followed by a B-phase representing the background activity. CAP is considered a physiological marker of sleep instability. Despite its informative nature, the clinical applications remain limited as CAP analysis is a time-consuming activity. In order to overcome this limit, several automatic detection methods were recently developed. In this paper, two new dimensions were investigated in the attempt to optimize novel, efficient and automatic detection algorithms: 1) many electroencephalographic leads were compared to identify the best local performance, and 2) the global contribution of the concurrent detection across several derivations to CAP identification. The developed algorithms were tested on 41 polysomnographic recordings from normal (n = 8) and pathological (n = 33) subjects. In comparison with the visual CAP analysis as the gold standard, the performance of each algorithm was evaluated. Locally, the detection on the F4-C4 derivation showed the best performance in comparison with all other leads, providing practical suggestions of electrode montage when a lean and minimally invasive approach is preferable. A further improvement in the detection was achieved by a multi-trace method, the Global Analysis—Common Events, to be applied when several recording derivations are available. Moreover, CAP time and CAP rate obtained with these algorithms positively correlated with the ones identified by the scorer. These preliminary findings support efficient automated ways for the evaluation of the sleep instability, generalizable to both normal and pathological subjects affected by different sleep disorders.

Effects of onion extract containing concentrated cysteine sulfoxides on sleep quality: a randomized, double-blind, placebo-controlled, crossover study

The objective of this randomized, double-blind, placebo-controlled, crossover study was to examine the effects of onion extract containing concentrated cysteine sulfoxides on improving sleep quality. In total, 30 healthy men and women who were dissatisfied with their sleep consumed the test food sample (onion extract tablets) for 5 days. The delta power during non-rapid eye movement sleep and the delta power per minute in the first sleep cycle increased significantly with the intake of onion extract containing concentrated cysteine sulfoxides compared with the intake of placebo. A significant decline in sleep latency was also observed. Salivary α-amylase level, a stress indicator, decreased significantly with the intake of onion extract containing concentrated cysteine sulfoxides compared with the intake of placebo. These findings indicate that onion extract containing concentrated cysteine sulfoxides alleviates stress, improves the quality of sleep and promotes smooth transition into sleep.

The Role of Animal Models in Developing Pharmacotherapy for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a highly prevalent disease characterized by recurrent closure of the upper airway during sleep. It has a complex pathophysiology involving four main phenotypes. An abnormal upper airway anatomy is the key factor that predisposes to sleep-related collapse of the pharynx, but it may not be sufficient for OSA development. Non-anatomical traits, including (1) a compromised neuromuscular response of the upper airway to obstruction, (2) an unstable respiratory control (high loop gain), and (3) a low arousal threshold, predict the development of OSA in association with anatomical abnormalities. Current therapies for OSA, such as continuous positive airway pressure (CPAP) and oral appliances, have poor adherence or variable efficacy among patients. The search for novel therapeutic approaches for OSA, including pharmacological agents, has been pursued over the past years. New insights into OSA pharmacotherapy have been provided by preclinical studies, which highlight the importance of appropriate use of animal models of OSA, their applicability, and limitations. In the present review, we discuss potential pharmacological targets for OSA discovered using animal models.

Pharmacological interventions for benzodiazepine discontinuation in chronic benzodiazepine users

BACKGROUND

Prolonged treatment with benzodiazepines is common practice despite clinical recommendations of short-term use. Benzodiazepines are used by approximately 4% of the general population, with increased prevalence in psychiatric populations and the elderly. After long-term use it is often difficult to discontinue benzodiazepines due to psychological and physiological dependence. This review investigated if pharmacological interventions can facilitate benzodiazepine tapering.

OBJECTIVES

To assess the benefits and harms of pharmacological interventions to facilitate discontinuation of chronic benzodiazepine use.

SEARCH METHODS

We searched the following electronic databases up to October 2017: Cochrane Drugs and Alcohol Group's Specialised Register of Trials, CENTRAL, PubMed, Embase, CINAHL, and ISI Web of Science. We also searched ClinicalTrials.gov, the WHO ICTRP, and ISRCTN registry, and checked the reference lists of included studies for further references to relevant randomised controlled trials.

SELECTION CRITERIA

We included randomised controlled trials comparing pharmacological treatment versus placebo or no intervention or versus another pharmacological intervention in adults who had been treated with benzodiazepines for at least two months and/or fulfilled criteria for benzodiazepine dependence (any criteria).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 38 trials (involving 2543 participants), but we could only extract data from 35 trials with 2295 participants. Many different interventions were studied, and no single intervention was assessed in more than four trials. We extracted data on 18 different comparisons. The risk of bias was high in all trials but one. Trial Sequential Analysis showed imprecision for all comparisons.For benzodiazepine discontinuation, we found a potential benefit of valproate at end of intervention (1 study, 27 participants; risk ratio (RR) 2.55, 95% confidence interval (CI) 1.08 to 6.03; very low-quality evidence) and of tricyclic antidepressants at longest follow-up (1 study, 47 participants; RR 2.20, 95% CI 1.27 to 3.82; low-quality evidence).We found potentially positive effects on benzodiazepine withdrawal symptoms of pregabalin (1 study, 106 participants; mean difference (MD) -3.10 points, 95% CI -3.51 to -2.69; very low-quality evidence), captodiame (1 study, 81 participants; MD -1.00 points, 95% CI -1.13 to -0.87; very low-quality evidence), paroxetine (2 studies, 99 participants; MD -3.57 points, 95% CI -5.34 to -1.80; very low-quality evidence), tricyclic antidepressants (1 study, 38 participants; MD -19.78 points, 95% CI -20.25 to -19.31; very low-quality evidence), and flumazenil (3 studies, 58 participants; standardised mean difference -0.95, 95% CI -1.71 to -0.19; very low-quality evidence) at end of intervention. However, the positive effect of paroxetine on benzodiazepine withdrawal symptoms did not persist until longest follow-up (1 study, 54 participants; MD -0.13 points, 95% CI -4.03 to 3.77; very low-quality evidence).The following pharmacological interventions reduced symptoms of anxiety at end of intervention: carbamazepine (1 study, 36 participants; MD -6.00 points, 95% CI -9.58 to -2.42; very low-quality evidence), pregabalin (1 study, 106 participants; MD -4.80 points, 95% CI -5.28 to -4.32; very low-quality evidence), captodiame (1 study, 81 participants; MD -5.70 points, 95% CI -6.05 to -5.35; very low-quality evidence), paroxetine (2 studies, 99 participants; MD -6.75 points, 95% CI -9.64 to -3.86; very low-quality evidence), and flumazenil (1 study, 18 participants; MD -1.30 points, 95% CI -2.28 to -0.32; very low-quality evidence).Two pharmacological treatments seemed to reduce the proportion of participants that relapsed to benzodiazepine use: valproate (1 study, 27 participants; RR 0.31, 95% CI 0.11 to 0.90; very low-quality evidence) and cyamemazine (1 study, 124 participants; RR 0.33, 95% CI 0.14 to 0.78; very low-quality evidence). Alpidem decreased the proportion of participants with benzodiazepine discontinuation (1 study, 25 participants; RR 0.41, 95% CI 0.17 to 0.99; number needed to treat for an additional harmful outcome (NNTH) 2.3 participants; low-quality evidence) and increased the occurrence of withdrawal syndrome (1 study, 145 participants; RR 4.86, 95% CI 1.12 to 21.14; NNTH 5.9 participants; low-quality evidence). Likewise, magnesium aspartate decreased the proportion of participants discontinuing benzodiazepines (1 study, 144 participants; RR 0.80, 95% CI 0.66 to 0.96; NNTH 5.8; very low-quality evidence).Generally, adverse events were insufficiently reported. Specifically, one of the flumazenil trials was discontinued due to severe panic reactions.

AUTHORS' CONCLUSIONS

Given the low or very low quality of the evidence for the reported outcomes, and the small number of trials identified with a limited number of participants for each comparison, it is not possible to draw firm conclusions regarding pharmacological interventions to facilitate benzodiazepine discontinuation in chronic benzodiazepine users. Due to poor reporting, adverse events could not be reliably assessed across trials. More randomised controlled trials are required with less risk of systematic errors ('bias') and of random errors ('play of chance') and better and full reporting of patient-centred and long-term clinical outcomes. Such trials ought to be conducted independently of industry involvement.

Sleep spindles may predict response to cognitive-behavioral therapy for chronic insomnia

BACKGROUND

While cognitive-behavioral therapy for insomnia constitutes the first-line treatment for chronic insomnia, only few reports have investigated how sleep architecture relates to response to this treatment. In this pilot study, we aimed to determine whether pre-treatment sleep spindle density predicts treatment response to cognitive-behavioral therapy for insomnia.

METHODS

Twenty-four participants with chronic primary insomnia participated in a 6-week cognitive-behavioral therapy for insomnia performed in groups of 4-6 participants. Treatment response was assessed using the Pittsburgh Sleep Quality Index and the Insomnia Severity Index measured at pre- and post-treatment, and at 3- and 12-months' follow-up assessments. Secondary outcome measures were extracted from sleep diaries over 7 days and overnight polysomnography, obtained at pre- and post-treatment. Spindle density during stage N2-N3 sleep was extracted from polysomnography at pre-treatment. Hierarchical linear modeling analysis assessed whether sleep spindle density predicted response to cognitive-behavioral therapy.

RESULTS

After adjusting for age, sex, and education level, lower spindle density at pre-treatment predicted poorer response over the 12-month follow-up, as reflected by a smaller reduction in Pittsburgh Sleep Quality Index over time. Reduced spindle density also predicted lower improvements in sleep diary sleep efficiency and wake after sleep onset immediately after treatment. There were no significant associations between spindle density and changes in the Insomnia Severity Index or polysomnography variables over time.

CONCLUSION

These preliminary results suggest that inter-individual differences in sleep spindle density in insomnia may represent an endogenous biomarker predicting responsiveness to cognitive-behavioral therapy. Insomnia with altered spindle activity might constitute an insomnia subtype characterized by a neurophysiological vulnerability to sleep disruption associated with impaired responsiveness to cognitive-behavioral therapy.

Incidence, Characterization, and Predictors of Sleep Apnea in Consecutive Brain Injury Rehabilitation Admissions

OBJECTIVE

To prospectively examine the incidence and risk factors for sleep apnea in consecutive brain injury rehabilitation admissions.

SETTING

Inpatient neurorehabilitation hospital.

PARTICIPANTS

Participants (n = 86) were consecutive neurorehabilitation admissions.

DESIGN

Retrospective analysis of prospectively collected data.

MAIN MEASURES

Polysomnography.

RESULTS

Half (49%) of the sample was diagnosed with sleep apnea. For the full sample, univariate logistic regression revealed age (odds ratio: 1.08; 95% confidence interval: 1.04-1.11) and hypertension (odds ratio: 7.77; 95% confidence interval: 2.81-21.47) as significant predictors of sleep apnea diagnosis. Results of logistic regression conducted within the traumatic brain injury group revealed age (odds ratio: 1.07; 95% confidence interval: 1.02-1.13) as the only significant predictor of apnea diagnosis after adjustment for other variables. Hierarchical generalized linear regression models for the prediction of apnea severity (ie, apnea-hypopnea index found that Functional Independence Measure Cognition Score (P = .01) and age (P < .01) were significant predictors. Following adjustment for all other terms, only age (P < .01) remained significant.

CONCLUSION

Sleep apnea is prevalent in acute neurorehabilitation admissions and traditional risk profiles for sleep apnea may not effectively screen for the disorder. Given the progressive nature of obstructive sleep apnea and morbidity associated with even mild obstructive sleep apnea, early identification and intervention may address comorbidities influencing acute and long-term outcome.

Cellular and neurochemical basis of sleep stages in the thalamocortical network

The link between the combined action of neuromodulators in the brain and global brain states remains a mystery. In this study, using biophysically realistic models of the thalamocortical network, we identified the critical intrinsic and synaptic mechanisms, associated with the putative action of acetylcholine (ACh), GABA and monoamines, which lead to transitions between primary brain vigilance states (waking, non-rapid eye movement sleep [NREM] and REM sleep) within an ultradian cycle. Using ECoG recordings from humans and LFP recordings from cats and mice, we found that during NREM sleep the power of spindle and delta oscillations is negatively correlated in humans and positively correlated in animal recordings. We explained this discrepancy by the differences in the relative level of ACh. Overall, our study revealed the critical intrinsic and synaptic mechanisms through which different neuromodulators acting in combination result in characteristic brain EEG rhythms and transitions between sleep stages.

Japanese sake yeast supplementation improves the quality of sleep: a double-blind randomised controlled clinical trial

Activation of adenosine A2a receptors in cerebral neurons induces sleep in various mammals. It was previously found that Japanese sake yeast enriched in adenosine analogues activates A2a receptors in vitro and induces sleep in mice. Here it is reported that sake yeast activated A2a receptors in a cultured human cell line and improved human sleep quality in a clinical trial. Sake yeast activated A2a receptors in HEK cells in a dose-dependent manner with an EC50 of 40 μg mL(-1), and the activation was attenuated almost completely by the A2a receptor antagonist ZM241385 with an IC50 of 73 nm. In a double-blind placebo-controlled crossover clinical study, 68 healthy participants ingested tablets containing either 500 mg of sake yeast powder or a placebo (cellulose) 1 h before sleep for 4 days. Electroencephalograms were recorded during sleep at home with a portable device for 4 week days. Electroencephalogram analyses revealed that sake yeast supplementation significantly (P = 0.03) increased delta power during the first cycle of slow-wave sleep by 110%, without changing other sleep parameters. Sake yeast supplementation also significantly increased growth hormone secretion in the urine on awakening by 137% from 3.17 ± 0.41 (placebo) to 4.33 ± 0.62 (sake yeast) pg mg(-1) creatinine (P = 0.03). Subjective sleepiness (P = 0.02) and fatigue (P = 0.06) in the morning were improved by sake yeast. Given these benefits and the absence of adverse effects during the study period, it was concluded that sake yeast supplementation is an effective and safe way to support daily high-quality, deep sleep.

Book Review: Insomnia following Traumatic Brain Injury: A Review

Sleep disturbances after a traumatic brain injury (TBI) have received very little scientific attention despite the fact that several studies indicate that they may occur in 30% to 70% of patients. For individuals with TBI, problems falling asleep or maintaining sleep can exacerbate other symptoms such as pain, cognitive deficits, fatigue, or irritability. Sleep disturbances can thus compromise the rehabilitation process and the ability to return to work. This article reviews the evidence on the epidemiology, etiology, and treatment of insomnia in the context of TBI and proposes areas for future research. Prevalence estimates of insomnia complaints in TBI patients are summarized. Potential etiological factors (i.e., lesions to the nervous system, anxiety) and possible consequences of insomnia (i.e., fatigue, cognitive problems) in the context of TBI are discussed. Finally, pharmacological and psychological treatments previously shown effective to treat insomnia in healthy individuals are discussed as valuable treatment options for TBI patients. Increased knowledge about the high prevalence, diagnosis, and potential etiological factors of insomnia following TBI may promote a better identification, evaluation, and treatment of sleeping difficulties in this population.

Objective and subjective sleep quality: Melatonin versus placebo add-on treatment in patients with schizophrenia or bipolar disorder withdrawing from long-term benzodiazepine use

Benzodiazepines are frequently long-term prescribed for the treatment of patients with severe mental illness. This prescribing practice is problematic because of well-described side effects including risk of dependence. We examined the efficacy of prolonged-release melatonin on objective and subjective sleep quality during benzodiazepine discontinuation and whether sleep variables were associated with benzodiazepine withdrawal. Eligible patients included adults with a diagnosis of schizophrenia, schizoaffective disorder, or bipolar disorder and long-term use of benzodiazepines in combination with antipsychotics. All participants gradually tapered the use of benzodiazepines after randomization to add-on treatment with melatonin versus placebo. Here we report a subsample of 23 patients undergoing sleep recordings (one-night polysomnography) and 55 patients participating in subjective sleep quality ratings. Melatonin had no effect on objective sleep efficiency, but significantly improved self-reported sleep quality. Reduced benzodiazepine dosage at the 24-week follow-up was associated with a significantly decreased proportion of stage 2 sleep. These results indicate that prolonged-release melatonin has some efficacy for self-reported sleep quality after gradual benzodiazepine dose reduction, and that benzodiazepine discontinuation is not associated with rebound insomnia in medicated patients with severe mental illness. However, these findings were limited by a small sample size and a low retention rate.

Suvorexant for the treatment of insomnia

Suvorexant (Belsorma(®)) is the first orexin receptor antagonist approved by the US FDA (August 2014) for insomnia treatment. Following comprehensive Phase II/III studies, with up to 12 months of treatment in adult and elderly patients, there is little doubt that suvorexant induces and maintains sleep. However, the FDA and sponsor disagreed about effective versus safe doses (November 2012). The FDA considered that 5-15 mg were efficient and probably safe, whereas the sponsors had proposed 15-40 mg. The final approved doses are 5, 10, 15 and 20 mg. The major issues are next-morning somnolence and safety as seen in driving tests, with possible signs of muscle weakness, weird dreams, sleep walking, other nighttime behaviors and suicidal ideation. Despite its limitations, suvorexant's market entry offers a truly novel treatment for insomnia, paving the way for follow-up compounds and opening therapeutic avenues in other disorders for orexin receptor modulating compounds.

Propofol versus flunitrazepam for inducing and maintaining sleep in postoperative ICU patients

Context:

Sleep deprivation is a common problem on intensive care units (ICUs) influencing not only cognition, but also cellular functions. An appropriate sleep-wake cycle should therefore be maintained to improve patients’ outcome. Multiple disruptive factors on ICUs necessitate the administration of sedating and sleep-promoting drugs for patients who are not analgo-sedated.

Aims:

The objective of the present study was to evaluate sleep quantity and sleep quality in ICU patients receiving either propofol or flunitrazepam.

Settings and Design:

Monocentric, randomized, double-blinded trial.

Materials and Methods:

A total of 66 ICU patients were enrolled in the study (flunitrazepam n = 32, propofol n = 34). Propofol was injected continuously (2 mg/kg/h), flunitrazepam as a bolus dose (0.015 mg/kg). Differences between groups were evaluated using a standardized sleep diary and the bispectral index (BIS).

Statistical Analysis Used:

Group comparisons were performed by Mann-Whitney U-Test. P < 0.05 was considered to be statistically significant.

Results:

Sleep quality and the frequency of awakenings were significantly better in the propofol group (Pg). In the same group lower BIS values were recorded (median BIS propofol 74.05, flunitrazepam 78.7 [P = 0.016]). BIS values had to be classified predominantly to slow-wave sleep under propofol and light sleep after administration of flunitrazepam. Sleep quality improved in the Pg with decreasing frequency of awakenings and in the flunitrazepam group with increasing sleep duration.

Conclusions:

Continuous low-dose injection of propofol for promoting and maintaining night sleep in ICU patients who are not analgo-sedated was superior to flunitrazepam regarding sleep quality and sleep structure.

Use of non-benzodiazepine sedative hypnotics and risk of falls in older men

BACKGROUND

To ascertain whether use of non-benzodiazepine sedative-hypnotics is associated with risk of falls and compare this to risk of falls associated with use of benzodiazepines.

METHODS

Among 4450 community-dwelling men, aged 71 years and older, enrolled in the population-based prospective cohort study, Osteoporotic Fractures in Men (MrOS), use of nonbenzodiazepine sedative-hypnotics and benzodiazepines was assessed by interview and verified from medication containers at the third annual visit of the MrOS study. Falls in the subsequent one-year period were ascertained by tri-annual questionnaires and a computerized dictionary used to categorize type of medication.

RESULTS

In age-adjusted models, non-benzodiazepine sedative hypnotic use was associated with an increased risk of any falls (one or more falls) (RR 1.44, 95% CI 1.15, 1.81) and recurrent falls (2 or more falls) (RR 1.51, 95% CI 1.07, 2.14). Use of benzodiazepines was associated with a similar increase in age-adjusted risk of falling. Depressive symptoms, inability to stand from a chair, and instrumental activities of daily living (IADL) impairment modestly attenuated these associations. The association between non-benzodiazepine sedative-hypnotic use and falls was most pronounced among men without a history of falls in the previous year: in a multivariable model controlling for multiple potential confounders, the RR of any falls was 1.74 (95% CI 1.13, 2.68) in this subgroup.

CONCLUSIONS

Use of non-benzodiazepine sedative-hypnotics is associated with an increased risk of falls. Non-pharmacologic approaches to sleep disturbances may represent the safest approach to sleep difficulties in older adults.

Alterations in cyclic alternating pattern associated with phase advanced sleep are differentially modulated by gaboxadol and zolpidem

OBJECTIVE

to evaluate cyclic alternating pattern (CAP) in a phase advance model of transient insomnia and the effects of gaboxadol and zolpidem.

DESIGN

a randomized, double-blind, cross-over study in which habitual sleep time was advanced by 4 h.

SETTING

6 sleep research laboratories in US PARTICIPANTS: 55 healthy subjects (18-57 y)

INTERVENTIONS

Gaboxadol 15 mg (GBX), zolpidem 10 mg (ZOL), and placebo (PBO).

MEASUREMENTS

routine polysomnographic (PSG) measures, CAP, spectral power density, and self-reported sleep measures

RESULTS

The phase advance model of transient insomnia produced significant changes in CAP parameters. Both GBX and ZOL significantly and differentially modified CAP parameters in the direction of more stable sleep. GBX brought the CAP rate in stage 1 sleep and slow wave sleep (SWS) closer to baseline levels but did not significantly change the CAP rate in stage 2. ZOL reduced the CAP rate in stage 2 to near baseline levels, whereas the CAP rate in stage 1 and SWS was reduced substantially below baseline levels. The CAP parameter A1 index (associated with SWS and sleep continuity) showed the highest correlation with self-reported sleep quality, higher than any traditional PSG, spectral, or other self-reported measures.

CONCLUSION

disruptions in CAP produced by phase advanced sleep were significantly and differentially modulated by gaboxadol and zolpidem. The relative independence of CAP parameters from other electrophysiological measures of sleep, their high sensitivity to sleep disruption, and their strong association with subjective sleep quality suggest that CAP variables may serve as valuable endpoints in future insomnia research.

Trazodone for the treatment of fibromyalgia: an open-label, 12-week study

Background

Despite its frequent use as a hypnotic, trazodone has not been systematically assessed in fibromyalgia patients. In the present study have we evaluated the potential effectiveness and tolerability of trazodone in the treatment of fibromyalgia.

Methods

A flexible dose of trazodone (50-300 mg/day), was administered to 66 fibromyalgia patients for 12 weeks. The primary outcome measure was the Pittsburgh Sleep Quality Index (PSQI). Secondary outcome measures included the Fibromyalgia Impact Questionnaire (FIQ), the Beck Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS), the Brief Pain Inventory (BPI), the Short-Form Health Survey (SF-36), and the Patients' Global Improvement Scale (PGI). Trazodone's emergent adverse reactions were recorded. Data were analyzed with repeated measures one-way ANOVA and paired Student's t test.

Results

Trazodone markedly improved sleep quality, with large effect sizes in total PSQI score as well on sleep quality, sleep duration and sleep efficiency. Significant improvement, although with moderate effect sizes, were also observed in total FIQ scores, anxiety and depression scores (both HADS and BDI), and pain interference with daily activities. Unexpectedly, the most frequent and severe side effect associated with trazodone in our sample was tachycardia, which was reported by 14 (21.2%) patients.

Conclusions

In doses higher than those usually prescribed as hypnotic, the utility of trazodone in fibromyalgia management surpasses its hypnotic activity. However, the emergence of tachycardia should be closely monitored.

Trial registration

This trial has been registered with ClinicalTrials.gov number NCT-00791739.

Expert opinion on pharmacotherapy of narcolepsy

IMPORTANCE TO THE FIELD

Narcolepsy is a neurodegenerative disorder resulting in the instability of the sleep-wake cycle and marked by low levels of hypocretin in cerebrospinal fluid. Sleep instability is marked by brisk, sleep-onset REM periods and sleep fragmentation, while the waking state is interrupted by the intrusion of REM sleep and sometimes accompanied by cataplectic attacks.

AREAS COVERED IN THIS REVIEW

Current pharmacologic interventions that aim to address three primary features of this disorder; excessive daytime sleepiness (EDS), cataplexy and automatic behaviors, and sleep fragmentation. We review and compare the use of traditional and new stimulants in the treatment of EDS. For the treatment of cataplexy and automatic behaviors, serotonergic and noradrenergic agents are considered. The role of gamma-hydroxybutyrate (GHB) is also explored in its ability to reduce daytime sleepiness and catapletic attacks and to consolidate sleep. Findings are based on a PubMed literature search of clinical and basic science research papers spanning 1977-2009.

WHAT THE READER WILL GAIN

A comprehensive understanding of the various existing and promising future treatments for narcolepsy. For each of these treatments, we evaluate risks versus benefits of treatment, and proposed pharmacologic mechanisms of action. We conclude with a review of new treatment approaches, including thyrotropin-releasing hormone (TRH), histamine agonists, immunotherapy and hypocretin replacement therapies.

TAKE HOME MESSAGE

Narcolepsy is an autoimmune, neurodegenerative disorder that results in significant sleep-wake instability with or without cataplectic attacks. Current treatments aim symptomatically to reconsolidate the sleep and waking states and to reduce daytime attacks of cataplexy. Future treatments aim primarily towards correcting the causal deficiency of hypocretin or preventing the autoimmune response that results in the loss of hypocretin cells.

Cerebrospinal hypocretin, daytime sleepiness and sleep architecture in Parkinson's disease dementia

Excessive daytime sleepiness is common in Parkinson's disease and has been associated with Parkinson's disease-related dementia. Narcoleptic features have been observed in Parkinson's disease patients with excessive daytime sleepiness and hypocretin cell loss has been found in the hypothalamus of Parkinson's disease patients, in association with advanced disease. However, studies on cerebrospinal fluid levels of hypocretin-1 (orexin A) in Parkinson's disease have been inconclusive. Reports of sleep studies in Parkinson's disease patients with and without excessive daytime sleepiness have also been disparate, pointing towards a variety of causes underlying excessive daytime sleepiness. In this study, we aimed to measure cerebrospinal fluid hypocretin-1 levels in Parkinson's disease patients with and without dementia and to study their relationship to dementia and clinical excessive daytime sleepiness, as well as to describe potentially related sleep architecture changes. Twenty-one Parkinson's disease patients without dementia and 20 Parkinson's disease patients with dementia, along with 22 control subjects without sleep complaints, were included. Both Epworth sleepiness scale, obtained with the help of the caregivers, and mini-mental state examination were recorded. Lumbar cerebrospinal fluid hypocretin-1 levels were measured in all individuals using a radio-immunoassay technique. Additionally, eight Parkinson's disease patients without dementia and seven Parkinson's disease patients with dementia underwent video-polysomnogram and multiple sleep latencies test. Epworth sleepiness scale scores were higher in Parkinson's disease patients without dementia and Parkinson's disease patients with dementia than controls (P < 0.01) and scores >10 were more frequent in Parkinson's disease patients with dementia than in Parkinson's disease patients without dementia (P = 0.04). Cerebrospinal fluid hypocretin-1 levels were similar among groups (controls = 321.15 +/- 47.15 pg/ml; without dementia = 300.99 +/- 58.68 pg/ml; with dementia = 309.94 +/- 65.95 pg/ml; P = 0.67), and unrelated to either epworth sleepiness scale or mini-mental state examination. Dominant occipital frequency awake was slower in Parkinson's disease patients with dementia than Parkinson's disease patients without dementia (P = 0.05). Presence of slow dominant occipital frequency and/or loss of normal non-rapid eye movement sleep architecture was more frequent among Parkinson's disease patients with dementia (P = 0.029). Thus, excessive daytime sleepiness is more frequent in Parkinson's disease patients with dementia than Parkinson's disease patients without dementia, but lumbar cerebrospinal fluid hypocretin-1 levels are normal and unrelated to severity of sleepiness or the cognitive status. Lumbar cerebrospinal fluid does not accurately reflect the hypocretin cell loss known to occur in the hypothalamus of advanced Parkinson's disease. Alternatively, mechanisms other than hypocretin cells dysfunction may be responsible for excessive daytime sleepiness and the sleep architecture alterations seen in these patients.

Characteristics associated with benzodiazepine usage in elderly outpatients in Taiwan

OBJECTIVE

To investigate benzodiazepine usage and the characteristics associated with usage among elderly outpatients in Taiwan.

METHODS

This was an observational study of subjects who were enrolled in the National Health Insurance program and aged at least 65 in 2002. They were grouped according to treatment period and mean dosage. An ordered logit regression model was used to evaluate associations of characteristics with benzodiazepine usage.

RESULTS

Of the 4,267 elderly people included, 1,826 had received at least one prescription for benzodiazepines. The 1-year prevalence of benzodiazepine usage by elderly outpatients was approximately 43%. Characteristics associated with receiving benzodiazepine therapy included female gender, displaying comorbid insomnia, anxiety, depression, other mental diseases, cardiovascular disease, cancer, chronic obstructive pulmonary disease, arthritis, and previous use of benzodiazepines. Individuals older than 75 years, with comorbid insomnia, anxiety, depression, other mental diseases, cardiovascular disease, cancer, being in previous receipt of benzodiazepines, or high prescription-overlap ratio were more likely to receive longer treatment. Individuals with insomnia, anxiety, depression, and previous use of higher cumulative dosage of benzodiazepine were more likely to receive higher-dosage therapy.

CONCLUSIONS

Mental disorders and previous exposure to higher cumulative dosages of benzodiazepines are associated with an increased likelihood of receiving benzodiazepine therapy, longer treatment, and a higher mean dosage. Older individuals, less likely to receive higher dosage benzodiazepine therapy, are more likely to receive more prolonged therapy. Women are more likely to receive benzodiazepine therapy, but both men and women have comparable benzodiazepine usage patterns.

Efficacy of the selective extrasynaptic GABAA agonist, gaboxadol, in a model of transient insomnia: A randomized, controlled clinical trial

OBJECTIVE

The hypnotic efficacy of gaboxadol, a selective extrasynaptic GABA A agonist (SEGA), was evaluated in a phase-advance model of transient insomnia.

METHODS

Healthy subjects (18-64 years) completed a randomized, double-blind, parallel group study in which the sleep period was advanced 4h from habitual sleep time. Polysomnographic (PSG) and self-reported sleep measures were used to compare gaboxadol 10mg (N =271) and 15 mg (N =274) versus placebo (N =277).

RESULTS

In the placebo group, the phase-advance procedure disrupted sleep maintenance as measured by PSG wakefulness after sleep onset (WASO) and self-reported WASO (sWASO), and also, to a lesser extent, disrupted sleep onset as measured by PSG latency to persistent sleep (LPS) and self-reported time to sleep onset (sTSO). Both doses of gaboxadol decreased WASO and sWASO versus placebo (p <or= 0.05). Gaboxadol 15 mg also reduced LPS versus placebo (p <or= 0.01) and both doses reduced sTSO versus placebo (p <or= 0.01). PSG and self-reported total sleep time as well as ratings of sleep quality were improved with both gaboxadol doses relative to placebo (all p <or= 0.01 or better). The amount of slow wave sleep (SWS) was greater with both doses of gaboxadol than with placebo (p <or= 0.001). No group differences in the amount of rapid eye movement sleep were found. Most PSG and self-report measures indicated a mild dose response. The percentage of subjects with adverse events was low (<10% in any treatment group) and all were mild or moderate; none were serious and gaboxadol did not impact morning gait or coordination.

CONCLUSIONS

Gaboxadol 10 and 15 mg were efficacious in significantly reducing the sleep maintenance and sleep onset disruption produced by this model of transient insomnia, with effects generally being most pronounced for the 15 mg dose. Gaboxadol also enhanced SWS.

Efficacy of cognitive-behavioral therapy for insomnia associated with traumatic brain injury: a single-case experimental design

OBJECTIVE

To test the efficacy of a cognitive-behavioral therapy (CBT) for insomnia in persons having sustained traumatic brain injury (TBI).

DESIGN

Single-case design with multiple baselines across participants.

SETTING

Outpatient rehabilitation center.

PARTICIPANTS

Eleven subjects having sustained mild to severe TBI who developed insomnia after the injury.

INTERVENTION

Eight-week CBT for insomnia including stimulus control, sleep restriction, cognitive restructuring, sleep hygiene education, and fatigue management.

MAIN OUTCOME MEASURES

Total wake time, sleep efficiency, and diagnostic criteria.

RESULTS

Visual analyses, corroborated by intervention time series analyses and t tests, revealed clinically and statistically significant reductions in total wake time and sleep efficiency for 8 (73%) of 11 participants. An average reduction of 53.9% in total wake time was observed across participants from pre- to post-treatment. Progress was in general well maintained at the 1-month and 3-month follow-ups. The average sleep efficiency augmented significantly from pretreatment (77.2%) to post-treatment (87.9%), and also by the 3-month follow-up (90.9%). Improvements in sleep were accompanied by a reduction in symptoms of general and physical fatigue.

CONCLUSIONS

The results of this study show that psychologic interventions for insomnia are a promising therapeutic avenue for TBI survivors.

Short-term treatment with gaboxadol improves sleep maintenance and enhances slow wave sleep in adult patients with primary insomnia

RATIONALE

Gaboxadol is a selective extrasynaptic GABA(A) agonist, previously in development for the treatment of insomniac patients.

OBJECTIVE

To evaluate the acute efficacy and safety of gaboxadol in primary insomnia (PI).

METHODS

This was a randomised, double-blind, four-way crossover, polysomnograph study comparing gaboxadol 10 and 20 mg (GBX20) to placebo in 40 adults with the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria for PI. Zolpidem 10 mg was used as an active reference. Treatment was administered on two consecutive nights in each treatment session. Next-day residual effects were evaluated 2 and 9 h after lights on.

RESULTS

Efficacy analysis included the per-protocol population (n = 38) from night 2. GBX20 reduced wake after sleep onset (p < 0.01). Both doses of gaboxadol, but not zolpidem, reduced the number of night awakenings (p < 0.001). GBX20 and zolpidem increased total sleep time (p < 0.05). Neither dose of gaboxadol nor zolpidem significantly reduced sleep onset latency, although a trend was seen for zolpidem. Gaboxadol enhanced slow wave sleep (SWS) dose-dependently (gaboxadol 10 mg: p < 0.01, GBX20: p < 0.001). Patients reported improved sleep quality following GBX20 (p < 0.05). Both doses of gaboxadol were generally well tolerated with almost exclusively mild to moderately severe adverse events (AEs). More frequent and severe AEs followed GBX20. No serious AEs were reported. No drug treatment was associated with next-day residual effects.

CONCLUSION

Acute administration of gaboxadol improves sleep maintenance and enhances SWS in a dose-dependent manner in adult patients with PI. Gaboxadol was not associated with next-day residual effects. Gaboxadol was generally well tolerated, although gaboxadol showed a dose-dependent increase in incidence and severity of AEs.

The effect of placebo administration on the first-night effect in healthy young volunteers

The first-night effect is a well-known phenomenon that is considered to result from a subject's lack of adaptation to the unfamiliar environment of a sleep laboratory and to the technical equipment used for polysomnography. The effect has been explored as a laboratory model for transient insomnia. The main characteristics of this effect are short total sleep time (TST) and rapid eye movement (REM) sleep, a lower sleep efficiency index, and longer REM sleep latency. Previous studies have reported that personality traits (such as trait anxiety) are a potential cause of the first-night effect and that the placebo effect is closely related to the anxiety levels of the subjects. To the best of our knowledge, there are no reports regarding the effects of a placebo on first-night sleep. This omission can be explained by the fact that the polysomnographic recordings obtained during the first night of a study are generally excluded from the analysis in order to avoid the inclusion of the first-night effect. In the present study, 8 male university students were subjected to polysomnographic examinations during drug-free, placebo-administration, and benzodiazepine-administration conditions in order to clarify the placebo effect on sleep during consecutive nights, particularly on the first night. The recordings for each condition were conducted for 4 consecutive nights. A placebo or 5 mg nitrazepam was administered at 2230 h using a double-blind crossover design, while no drug was administered during the drug-free condition. There was a 10-day interval between the examination of each condition. Polysomnographic recording was started at 2300 h and continued until the natural awakening of the subjects on the next morning. Subsequently, the subjects were requested to fill in a rating scale that is used to evaluate the subjective perception of sleep. An increase in stage-2 sleep associated with the first-night effect was observed on the first night during the drug-free and placebo-administration conditions. However, REM sleep reduction associated with the first-night effect was detected on the first night during the drug-free condition; this decrease in REM sleep was counteracted by the placebo during the placebo-administration condition. The nitrazepam, but not the placebo, decreased both slow-wave sleep (SWS) and REM sleep. The values for the tendency to fall asleep, feeling refreshed upon awakening in the morning, and the tension upon awakening in the morning were improved to a greater extent by the placebo and nitrazepam administrations than when no drug was administered. These results demonstrate the possibility that placebo administration may have a hypnotic/anxiolytic effect and may improve transient insomnia without causing SWS and REM sleep reductions.

Extract of Ganoderma lucidum potentiates pentobarbital-induced sleep via a GABAergic mechanism

Ganoderma lucidum has been used for the treatment of a variety of diseases. For the first time here we report a detailed study on the mechanisms and effects of G. lucidum aqueous extract (GLE) on sleep and its sedative activity. GLE showed no effects on sleep architecture in normal rats at doses of 80 and 120 mg/kg. However, GLE significantly decreased sleep latency, increased sleeping time, non-REM sleep time and light sleep time in pentobarbital-treated rats. Suppression of locomotor activity in normal mice induced by GLE was also observed. Flumazenil, a benzodiazepine receptor antagonist, at a dose of 3.5 mg/kg showed a significant antagonistic effect on the shortening in sleep latency, increase in sleeping time, non-REM sleep time or light sleep time in pentobarbital-treated rat induced by GLE. Significant effect was also observed with GLE on delta activity during non-REM sleep and flumazenil did not block this effect. In conclusion, GLE may be a herb having benzodiazepine-like hypnotic activity at least in part.

Effects of some H1-antagonists on the sleep-wake cycle in sleep-disturbed rats

The present study was undertaken to investigate the effects of some H(1)-antagonists on the sleep-wake cycle in sleep-disturbed rats in comparison with those of nitrazepam. Electrodes were chronically implanted into the frontal cortex and the dorsal neck muscle of rats for the electroencephalogram (EEG) and electromyogram (EMG), respectively. EEG and EMG were recorded with an electroencephalograph. SleepSign ver. 2.0 was used for EEG and EMG analysis. The total times of waking, non-rapid eye movement (non-REM), and rapid eye movement (REM) sleep were measured from 10:00 to 16:00. Nitrazepam showed a significant decrease in sleep latency, total waking time, and delta activity and an increase in the total non-REM sleep time. A significant decrease in the sleep latency was observed with diphenhydramine, chlorpheniramine, and cyproheptadine. Cyproheptadine also caused a significant decrease in the total waking time and increases in total non-REM sleep time, REM sleep time, slow wave sleep, and delta activity, although no remarkable effects were observed with diphenhydramine and chlorpheniramine. In conclusion, cyproheptadine can be useful as a hypnotic, having not only sleep inducing-effects, but also sleep quantity- and quality-increasing effects.

Pharmacotherapy for disordered sleep in post-traumatic stress disorder: a systematic review

Sleep disorders, such as insomnia and nightmares, are common problems in post-traumatic stress disorder (PTSD), exert a strong negative influence on the quality of life and are a great challenge for clinical psychiatry. Several studies have reported on the efficacy of drugs for the treatment of PTSD-related sleep disorders. These studies have not been systematically reviewed. This is the first review on the effectiveness of sleep medication in PTSD. We performed a Medline, EMBASE and Cochrane Library Indexed search, using the keywords: PTSD, pharmacotherapy, therapy, sleep, nightmares, insomnia and review. From this database, English-language, human subject, data driven papers published after 1980 were selected. Forty eight articles are discussed. Open-label and case studies suggest efficacy for some antidepressants, anticonvulsants and atypical antipsychotics. Only a few placebo-controlled studies have been published. They show promising results for the atypical antipsychotic olanzapine, and the alpha1-adrenoceptor antagonist prazosin. In comparison to the incidence and impact of sleep complaints in PTSD, the pharmacotherapeutic armamentarium for PTSD-related sleep complaints remains poorly investigated. Some recent studies show promising results, especially for alpha1-adrenoceptor and 5-HT2 receptor antagonists. However, randomized controlled trials with larger populations need to be conducted.

Eszopiclone, a Nonbenzodiazepine Sedative-Hypnotic Agent for the Treatment of Transient and Chronic Insomnia

OBJECTIVE

This paper reviews the pharmacologic and pharmacokinetic properties, clinical efficacy, and safety profile of the nonbenzodiazepine cyclopyrrolone agent eszopiclone in the management of adult patients with insomnia.

METHODS

Recent studies, abstracts, reviews, and consensus statements published in English were identified through searches of MEDLINE (1966-December 2005), International Pharmaceutical Abstracts (1970 December 2005), and PharmaProjects (1990-December 2005) using the search terms eszopiclone, cyclopyrrolone, insomnia, nonbenzodiazepine, and zopiclone enantiomer. Selected information provided by the manufacturer of eszopiclone was included, as were all pertinent clinical trials.

RESULTS

Eszopiclone is rapidly absorbed after oral administration, with Tmax achieved within approximately 1 hour and a terminal-phase elimination half-life of approximately 6 hours. Approximately 52% to 59% of a dose is weakly bound to plasma protein. Eszopiclone is extensively metabolized by oxidation and demethylation. In vitro studies have indicated that the cytochrome P450 (CYP) isozymes CYP3A4 and CYP2E1 are involved in the biotransformation of eszopiclone; therefore, drugs that induce or inhibit these CYP isozymes may affect the metabolism of eszopiclone. Eszopiclone is excreted in the urine as racemic zopiclone at <10% of the orally administered dose. Six Phase III clinical trials were identified that evaluated the safety profile and efficacy of eszopiclone, 1 in healthy subjects with transient insomnia and 5 in patients with primary chronic insomnia (3 in younger adults and 2 in the elderly). In the trials in younger adults, eszopiclone significantly improved sleep efficiency, sleep latency, wake time after sleep onset, number of awakenings, number of nights awakened weekly, total sleep time, and quality and depth of sleep compared with placebo (P<0.05). In the trials in elderly patients, who received eszopiclone 2 mg or placebo for 2 weeks, eszopiclone was associated with significantly shorter sleep latency compared with placebo (P<0.004), as well as a significant decrease in the cumulative number of naps (P<0.05). The most commonly reported drug-related, dose-responsive adverse event in clinical trials of eszopiclone 2 and 3 mg was bitter taste (17% and 34%, respectively), followed by dizziness (5% and 7%) and dry mouth (5% and 7%). Somnolence occurred at an incidence of 4% to 9% with both doses. Tolerance or rebound insomnia was not reported.

CONCLUSIONS

Eszopiclone represents an effective and well-tolerated option for the treatment of insomnia. In the absence of published studies comparing eszopiclone with similar hypnotic agents (eg, zolpidem, zaleplon, zopiclone), it is not yet possible to evaluate its efficacy relative to other agents used for insomnia.

Effect of zolpidem on sleep architecture and its next-morning residual effect in insomniac patients: a randomized crossover comparative study with brotizolam

This study was conducted to determine the effect of zolpidem (ZOL) 10 mg orally on the sleep architecture and the next-morning residual effect in patients with non-organic insomnia (ICD-10) as compared to the effect of brotizolam (BTM) 0.25 mg orally, a widely used short-acting benzodiazepine (BZD) hypnotic in Japan, in a randomized, crossover comparative study. Fourteen patients with non-organic insomnia (3 males and 11 females; mean age of 54.9+/-S.D. 8.9 years). First three nights with placebo, middle three nights with either ZOL 10 mg or BTM 0.25 mg, and last three nights again with placebo in each session (a total of two sessions). Primary endpoints were polysomnography findings of sleep stages, sleep parameters, and sleep latency (SL) in the morning to examine calculable sleepiness as a residual effect. Secondary endpoint was sleep quality assessed by self-assessment questionnaire. At 150 min after Tmax, both ZOL and BTM significantly increased stage 2 (S2), and ZOL showed significantly longer slow wave sleep (SWS; stage 3+4) as compared to BTM. Stage wake was significantly increased by ZOL at the first withdrawal night and by BTM at the second withdrawal night. ZOL did not affect SL after rising, whereas BTM showed significantly shorter SL. Both drugs reduced the number of nocturnal awakenings and improved subjective sleep quality. The common adverse drug reaction (ADR) was sleepiness (3 patients) in each treatment. All events were mild. No serious adverse events occurred. ZOL is as effective as BTM in improving subjective sleep quality in patients with psychophysiological insomnia (PPI). ZOL has advantages over BTM in having a unique profile of increasing SWS with less next-morning residual effect.

Effects of kava-kava extract on the sleep-wake cycle in sleep-disturbed rats

RATIONALE

Kava-kava extract may be useful as an herbal medicine for treatment of insomnia and anxiety.

OBJECTIVES

The present study was undertaken to investigate the effects of kava-kava extract on the sleep-wake cycle in comparison with that of flunitrazepam using sleep-disturbed rats.

METHODS

Electrodes for measurement of electroencephalogram (EEG) and electromyogram (EMG) were implanted into the frontal cortex and the dorsal neck muscle of rats. EEG and EMG were recorded with an electroencephalogram. SleepSign ver.2.0 was used for EEG and EMG analysis. Total times of wakefulness, non-rapid eye movement (non-REM) and REM sleep were measured from 09:00 to 15:00.

RESULTS

A significant shortening of the sleep latency in sleep-disturbed rats was observed following the administration of kava-kava extract at a dose of 300 mg/kg, while no effects were observed on the total waking and non-REM sleep time. On the other hand, flunitrazepam showed a significant shortening in sleep latency, decrease in total waking time and increase in total non-REM sleep time. Although the effects of flunitrazepam were antagonized by the benzodiazepine receptor antagonist flumazenil, the effect of kava-kava extract was not antagonized by flumazenil. Kava-kava extract showed a significant increase in delta activity during non-REM sleep in sleep-disturbed rats, whereas a significant decrease in delta power during non-REM sleep was observed with flunitrazepam. Flumazenil caused no significant effect on the changes in delta activity induced by both kava-kava extract and flunitrazepam.

CONCLUSIONS

Kava-kava extract is an herbal medicine having not only hypnotic effects, but also sleep quality-enhancement effects.

Effect of repeated gaboxadol administration on night sleep and next-day performance in healthy elderly subjects

Aging is associated with dramatic reductions in sleep continuity and sleep intensity. Since gaboxadol, a selective GABA(A) receptor agonist, has been demonstrated to improve sleep consolidation and promote deep sleep, it may be an effective hypnotic, particularly for elderly patients with insomnia. In the present study, we investigated the effects of subchronic gaboxadol administration on nocturnal sleep and its residual effects during the next days in elderly subjects. This was a randomized, double-blind, placebo-controlled, balanced crossover study in 10 healthy elderly subjects without sleep complaints. The subjects were administered either placebo or 15 mg gaboxadol hydrochloride at bedtime on three consecutive nights. Sleep was recorded during each night from 2300 to 0700 h and tests assessing attention (target detection, stroop test) and memory function (visual form recognition, immediate word recall, digit span) were applied at 0900, 1400, and 1700 h during the following days. Compared with placebo, gaboxadol significantly shortened subjective sleep onset latency and increased self-rated sleep intensity and quality. Polysomnographic recordings showed that it significantly decreased the number of awakenings, the amount of intermittent wakefulness, and stage 1, and increased slow wave sleep and stage 2. These effects were stable over the three nights. None of the subjects reported side effects. Next-day cognitive performance was not affected by gaboxadol. Gaboxadol persistently improved subjective and objective sleep quality and was devoid of residual effects. Thus, at the employed dose, it seems an effective hypnotic in elderly subjects.

Electroencephalographic properties of zaleplon, a non-benzodiazepine sedative/hypnotic, in rats

The encephalographic (EEG) properties of zaleplon were investigated in comparison with those of other sedative hypnotics in conscious rats with chronically implanted electrodes. The oral administration of zaleplon (0.25-1.0 mg/kg), triazolam (0.0625-0.25 mg/kg), zopiclone (1.0-4.0 mg/kg), brotizolam (0.0625-0.25 mg/kg), and nitrazepam (0.125-0.5 mg/kg) lengthened the total sleep in a dose-dependent manner. On distribution of sleep-wakefulness stages, zaleplon, in particular, increased the slow wave deep sleep (SWDS), whereas triazolam, brotizolam, and nitrazepam increased the slow wave light sleep (SWLS) in a dose-dependent manner. Zopiclone significantly increased the SWDS at a dose of 2 mg/kg and both the SWLS and the SWDS at a dose of 4 mg/kg. All tested hypnotics caused no influence on fast wave sleep (FWS) at doses tested. The appearance of the sleep-inducing activity of zaleplon was more rapid than those of any compounds tested, and zaleplon significantly increased the relative EEG power density in the delta frequency band over that of triazolam at 20 and 30 min after the administration in the spectral analysis. Therefore, the present findings suggest that the non-benzodiazepine zaleplon can be expected to exhibit high practical potential as a hypnotic and is characterized by an increase in SWDS with rapid onset of hypnotic action.

Hypnotic Activities of Chamomile and Passiflora Extracts in Sleep-Disturbed Rats

In the present study, we investigated hypnotic activities of chamomile and passiflora extracts using sleep-disturbed model rats. A significant decrease in sleep latency was observed with chamomile extract at a dose of 300 mg/kg, while passiflora extract showed no effects on sleep latency even at a dose of 3000 mg/kg. No significant effects were observed with both herbal extracts on total times of wakefulness, non-rapid eye movement (non-REM) sleep and REM sleep. Flumazenil, a benzodiazepine receptor antagonist, at a dose of 3 mg/kg showed a significant antagonistic effect on the shortening in sleep latency induced by chamomile extract. No significant effects were observed with chamomile and passiflora extracts on delta activity during non-REM sleep. In conclusion, chamomile extract is a herb having benzodiazepine-like hypnotic activity.

Rhythmic movement disorder and cyclic alternating pattern during sleep: A video-polysomnographic study in a 9-year-old boy

We report on polysomnographic findings in a 9-year-old boy affected by rhythmic movement disorder. The subject's rhythmic movements were found to be intimately linked to unstable nonrapid eye movement N-REM sleep, as shown by their close association with the A phases of the cyclic alternating pattern. We examine the complex interactions between arousal mechanisms and rhythmic movements occurring during sleep.